Hi bboris Try to look at this genius piece of hardware:https://www.tindie.com/products/Dead_Bug_Prototypes/extreme-low-power-data-logging-shield-for-arduino/It is based on the RTC DS1337 with a smart power-down function (or sleep-function)

NielsHolst

I am on a research team doing exactly that: We have put several bee hives on load cells to log weight at intervals of 10 min, or even 2 min, for several months. The load cells are expensive (little creep and 20 g precision) and are not an option for you.

My main message is: You should not worry about creep! You are interested in the daily weight gain, so make sure to measure weight at least every midnight. Subtract subsequent midnight readings and you'll achieve accurate measurements of daily weight gain, despite any creep (the creep during 24h is neglible). Add all the daily gains and you have the total amount of honey produced.

Bonus info: If you pile you hives high, wind will catch them and disturb your readings. Second to second weight readings could change by 1 kg! Therefore, to obtain one good reading, obtain several readings (say, 30 readings at 30s interval) and compute one reading as the average of that. Maybe calculate standard deviation also to get a measure how precise your average is.

Beekeepers all over the world are on to this, mesuring bee hive weight, temperature, rel. humidity, CO2, sound and vibrations! What this avalanche of data all means, is still an open question, except daily weight gain (or loss), that's easy to interpret and put to use, right?

NielsHolst

Hi Alain,In winter, if the bees go into hibernation and form a winter cluster, you will find that each hive looses weight at a constant rate. The rate likely depends on the size of the bee colony; it should be roughly proportional to the number of bees. Or, blame my intuition, maybe proportional to the cubic root of the number of bees, since they form a sphere?

Hi Lars, after finishing my prototype I ask myself why your prototype http://bildr.no/view/dUJJYWRC or http://forum.arduino.cc/index.php?topic=113534.msg1473176#msg1473176 looks like it looks. :-) You do not use a whole L-profile at the bottom. You have some gaps right and left on the vertical flank. Is this to mount it on a subbase? How is the load cell mounted on the lower L-profile?

Do you mount the scale on the front or back of the hive? Or left/right? Front vs. back has the disadvantage that weight is not divided equally in the hive. With honey in the back you have always higher load on the back side. If you put it right/left I think this is not so a problem. But mounting on a shorter side is more easy and more practically.

- Weight Platform Prototype I with Film Coated Plywood- Weight Platform Prototype II low cost module, weights only one side of the hive- Shields for Seeeduino Stalker (3.3 V) or Arduino Pro (3.3 V without RTC) and Yun / Uno (5 V) - a prototype with an ESP8266 on a breadboard - and also a prototype version with an Arduion Pro Mini and GSM

With the Seeduino Stalker and Arduino Pro as node I can use radio (RFM69) for data transfer, gateway is an Arduino Yun. I used this lib for RFM69: https://github.com/LowPowerLab/RFM69

The ESP uses Wifi and I can send the datasets via REST or via MQTT. Tested with the libs for Adafruit IO: https://github.com/adafruit/Adafruit_MQTT_Library and https://github.com/adafruit/Adafruit_IO_Arduino

I have also a Seeduino Stalker version with a GPRSbee, this sends the data via GSM/GPRS to a PHP script. Data visualization is done by Dygraphs http://dygraphs.com/ There is alos a GPRSbee lib for MQTT so switching from HTTP to MQTT should be possible easily (not tested yet).

We have also a Berlin (Germany) based group that develops a much more elaborated backend for bee monitoring purpose under the project name hiveeyesIt is based on BERadio, Kotori and Grafana mainly.

HI Clemens. Will you be making you prototypes available to replicate? - I am trying a similar project. Just wanting to be able to able to send weight via gsm and have it plotted on a graph. I will probably have 12 scales in different regions in NZ.Thanks!

Yes, I will publish code and constructions files. I am in a beta / alpha phase so not all is perfect, e.g. I have an design error in the PCB file, so I have to connect two pins to the Stalker directly and not over the shield. But one prototype with 2 DHT22 or 33 sensors, 5 DS18B20 and load cell is sending data every 20 minutes since over four weeks without any problem from my balcony. We set up an other installation some days ago with reduced sensors--only humidity/temperature outside and the weight--and this is running also.

You can find the graph of a test installation under http://open-hive.org/prototype-bee-scale/prototype-brandenburg.html

It is an interactive graph. You can select an area with the mouse--the timeline or the value range--so you can zoom in. With a double click you got back to all datapoints: Under the graph there are check boxes for every data series. If one chosen, for example only the weight and all other off, the script scales automatically the graphic so that the current values are populate the full scale range.

I use dygraphs http://dygraphs.com for visualization, a JavaScript library that deals with many data points. It runs as browser side JS, not on the server Thus, the first call may take more time when thousands records are loaded but if you then zoom in or out is the super fast.

The raw data, which the script directly processes, are simple comma-delimited values on the server:

Right in blue, a drilled cup with a DHT33 / combined humidity/temperature sensor for outdoors.

Below are the load cell for a unilateral weight with aluminum L-profiles.

On top 5 DS18B20 temperature sensors (can be more also) for the brood nest area.

Left side in curlers (against cementing) a DHT33 for indoor use.

All sensors are connected with round cables, which can be good passed through the screwable, waterproof cable glands on the case. An exception is the temperature array for inside (on top of the photo). There is a small board as flat cable connector. With this flat cable it is very easy to connect a pin header as as branch for the various temperature sensors between the combs.

The electronic case with a small solar cell under the transparent acrylic cover. The box is waterproof. The screws started after a wet day to rust. The box in the photo is on the balcony for about a month.

Inside the box it's quite busy:

At the bottom you can see the Seeeduino Stalker (red board), an Arduino derivative with additional clock (RTC), a charging circuit for solar panel and Lipo and a bee socket. "Bee socket" has nothing to do with bees ... haha! On the bee socket, the GSM / GPRS module sits, with "SIM800" print.

Right (white) is the self-designed shield with the load cells IC, some screw terminals, resistors, caps. Currently we have connections for a load cell and up to 3 DHTxx or DS18B20 sensors.

The small printed antenna for the modem is between board and housing, a black cable goes (almost invisible in the pic) from the modem to the antenna

The rechargeable battery, a Lipo, is under the Stalker and and so not visible.

Soem close ups Lipo, printed antenna, DHT on a smal breakout so that it fits in a curler, same DHT covered by a drilled Ikea cup for weather protection:

And I thought we were high tech when we would go out and lift each side of our hives with a fishing scale to see what they weighed ! The one thing we really had to watch for was that they had enough going into winter and in the spring, that they didn't go empty (the Seattle area is notorious for 2-3 weeks of nice weather in April which gets them all cranked up, the queen laying then 2-3 weeks of cold/rain/snow). You could lose a hive easily in late spring when that happened (cold / rain was also typically when your new queens arrived in the mail with no way to put them in the hives )

mikey-- you can't have too many gadgets or too much disk space !old engineering saying: 1+1 = 3 for sufficiently large values of 1 or small values of 3

[...] and lift each side of our hives with a fishing scale to see what they weighed !

There are a lot of commercial scales out that count on a double "H" as scale frame. The load cell is mounted on the "-" of the "H", see e.g. http://beewatch.de/waagen/stockwaagen/ . I've seen also some DIY prototypes of this scale type. Most wiggly but I don't know is it due to the concept at all or is it the amateur welding skills or the weak and too thin material.

Nevertheless I decided to count on a single side weighting process. Construction is easy, hive stands still stable, and of cause it is cheaper than a full-blown H frame.

I did some control measurement (Herold Magazin with Zander frames similar to a Langstroth Hive) last autumn--I did not write numbers down--but I had maximum 2 kg difference between the front and the back side of a hive.

What are your experiences, do you think a single side measurement (on the back) is sufficient? I asked in a German beekeeper discussion forum and most voted for a compete weighting procedure.

We were not that concerned with the accuracy as we were with making sure they were at least 80 pounds or more going into winter (pref. over 100) and they did not drop below about 35-40 in the spring to avoid them starving out. It doesn't surprise me you get different readings depending on the side - I would think the side with the most sun would be the heaviest, but I never actually checked them that way (and this was before all the problems with colony collapse we are seeing these days).

mikey-- you can't have too many gadgets or too much disk space !old engineering saying: 1+1 = 3 for sufficiently large values of 1 or small values of 3

It's my first post but I have been watching the progress of Lars project.So let's go:

I have a similar situation with the beehives.I want to monitor the weight of a freezer full of product to see if it is getting empty (when it becomes light), to send more products without the need to send someone to check.

This could also serve to warn about an interruption in the supply of freezer energy, so I could check what happened before the melting of the products.

I was thinking of installing the weight ranges between the wheels and the base of the freezer and a system that would send daily (or on demand) weight measurements by sms.Energy would be no problem because the system could be connected to power supply of freezer.